“Devastated is beyond words,” a police source said of Dunton, who after Thursday night’s fatal shooting retreated to the 25th Precinct station house and did little to hide his agony as he sat in stunned silence on the second floor.

The 30-year-old cop, who has been on the force 4½ years, sat there with his head in his hands, visibly shaken.

Occasionally, he’d stand up to pace back and forth, shaking his head.

“He was like in shock. It’s just so tragic,” said the source.

Dunton, whose wife is pregnant with their first child, is tormented by thoughts of his fallen colleague’s young children.

“He is heartbroken, distraught and upset. He sent his condolences [to Edwards’ family] saying how sorry he was,” said another police source. “He’s devastated because he left behind a family without a father.”

NYPD brass — including some chiefs and inspectors — sought him out to tell him they understood it was an accident, said the source.

Several superiors greeted him with handshakes and urged him to call if there is anything he needed.

Despite the show of support, “it’s hard to imagine his career won’t be ruined,” said a source.

Dunton has been placed on administrative leave while the shooting is being investigated.

He opened fire after he found the off-duty Edwards, with his gun drawn, chasing an alleged car thief on East 125th Street.

The accused thief reported that he heard Dunton, who didn’t realize Edwards was an cop, yell, “Police!” Edwards turned around with his gun drawn and that’s when Dunton opened fire.

However, even if Dunton isn’t charged criminally or within the department, people close to him said it will do little to ease his suffering.

“It’s not going to make any difference. It’s a fellow officer and he’s going to be devastated,” said a relative. “You couldn’t find a more dedicated, wonderful guy than Drew.”

Coincidentally, Edwards worked in the same precinct as Dunton’s ex-brother-in-law, said a source. That officer was married to Dunton’s wife’s sister.

The lifelong Long Island resident, who lives in Ridge, always dreamed of being a police officer, said a neighbor.

“He was so excited to become a cop. He really loved it. That’s what he wanted to do. He was very proud of it,” said Marie Jones, who lives next to Dunton’s parents.